1. Field of the Invention
This invention relates to apparatus for transporting lithographic plates used for printing newspapers or the like and, in particular, to apparatus for transporting such lithographic plates from a first location at which the plates are delivered by an overhead conveyor to a second location at a lower level.
2. Prior Art
A lithiographic plate of the kind used for printing newspapers or the like takes the form of an aluminium sheet having a thickness of the order of 0.3 mm and having one or both end regions thereof folded over to lie at approximately 30.degree. to the plane of the sheet. To transport the plate from one process station to another within the printing works, the plates are carried by an overhead conveyor which engages the folded end region of the plate.
The overhead conveyor normally travels close to a ceiling of the printing works and the conveyed lithographic plates must be successively fed downwardly towards a rotary press provided below the overhead conveyor. In addition, the lithographic plates must be temporarily stored during the downward movement.
The high speeds demanded in printing newspapers mean that the lithographic plate is normally of a size corresponding to two pages of a newspaper. Difficulties arise when attempting to move and store lithographic plates of this size, since the plates are not rigid.